Polymeric synthetic shingles or tiles, such as, for example, synthetic slate and shake materials can have a significant amount of thermal expansion and contraction when in use on a roof, due to variations in temperature conditions. It is important in installation to space adjacent shingles or tiles on a roof sufficiently close to each other so that gaps are not formed in the roof's protective covering, and sufficiently far apart so, that when the shingles expand and contract through temperature cycling, the shingles are not dislodged from the roof by such movement.
Such thermal expansion and contraction can lead to forces imposed on the edges of the roofing products where adjacent roofing products are abutted. In some instances, the forces may be large enough so that over repeated temperature changes during use, the shingle or tile fasteners may become dislodged from the roof, or the movement of the shingle or tile may lead to the development of stress cracking near contact points and cause damage to the shingle body.
Some shingle or tile products have integral spacers, called “nibs” along their side edges, that engage side edges of ad adjacent shingles or tiles to properly space adjacent products so that there is uniform spacing from shingle-to-shingle or from tile-to-tile, within a given course of shingles or tiles, as well as from course-to-course.
Some composite such products have their nibs hollowed out. Such shingles can be of generally solid construction except for the hollows inside the spacing nibs, where some material has been removed so that if the nib is pushed toward the body of the shingle or tile, there is potential for some give of the nib itself. The material from which the shingles or tiles are constructed can be sufficiently frangible that such “give” may cause the shingles or tiles to break.
Synthetic shake look panels typically have a locking arrangement where a portion of the panels overlap and slide by one another with expansion and contraction, along with a spacing gauge so that the panels are properly spaced at an installation temperature.
U.S. Pat. No. 6,939,036 discloses an installation method for a roof covering component, comprising providing first and second building components, one of said components being characterized by a predetermined expansion characteristic whereby said roofing component expands and contracts with temperature, said predetermined expansion characteristic causing a variation in distance between a reference point and a comparison point on the roofing component. The method can include determining a current temperature of the roofing component during one of installation and testing, by measuring said current temperature using a temperature sensor that is integral and affixed to at least one of said building components; equating the current temperature to a distance between the reference point and the comparison point at said current temperature; and assessing a position of the comparison point relative to the reference point for accommodating the expansion characteristic during subsequent changes in said current temperature.